<p>Is leaving 2 blank the same as getting 8 wrong? If so, it seems for a decent student (or maybe anyone) that guessing is better than leaving blank. Am I missing something?</p>
<p>Yeah, you are. When you get one wrong, you lose 1/4 of a point and you don't get the point that you would have gotten if you had gotten it correct. When you leave it blank, you gain nothing but lose nothing.</p>
<p>In a sense, getting a question wrong = - 5/4 of a point while leaving blank = -1 point.</p>
<p>So getting 8 wrong would be the equivalent of leaving 10 blank.</p>
<p>So should you never leave any blank and guess?</p>
<p>My son said the SAT Prep class teacher told them if they can narrow the answer down to 2 that they should guess. Else, leave it blank.</p>
<p>Whether you guess or not, every wrong answer is -1/4. Therefore, you're being scored as if you are guessing. So, you might as well guess, especially if you can eliminate one or two answers.</p>
<p>mathematically the strategy plays out this way ... </p>
<p>If you have no idea at about the correct answer and randomly guess, on average, your score will be the same as if you leave those questions blank.</p>
<p>However, if you eiminate at least one answer than guessing among the remaining answers leads to expected gain in your score. (This analysis works on average ... if a student is only unsure about 1 or 2 questions ... this approach will on average help ... but for a fair percentage of students hurt them)</p>